Effects of different homogenization treatments on color and stability of fish skin and bone steam-exploded broth

To address the issues of low utilization rate of freshwater surimi by-products (Fish skin and bone) and the poor stability of the broth system, we employed the steam explosion method to prepare fish skin and bone broth. We compared the effects of three homogenization methods (Colloid mill JTM, high-pressure homogenizer JZJ, and high-pressure microjet nano-homogenizer WSL) at different processing times (10, 20, 30, 40, 50 min) on the color and stability of the steam-exploded broth. The results show that after homogenization treatment using the three methods, the lightness (L^*) and whiteness (W) values increased, while the yellow-blue chromaticity (b^*) value and particle size decreased. The viscosity and absolute value of the ζ-potential increased. Meanwhile, the dispersion stability improved significantly (p<0.05). Compared with the JTM group, the JZJ and WSL groups could more significantly reduce the number of fat globules in the broth, and decrease the particle size of fat globules and fish skin and bone particles more significantly, which led to higher L^* and W values (p<0.05). The WSL group showed superior particle size distribution uniformity, although the average particle sizes among the three groups showed no significant difference. At the same homogenization time, the WSL group samples exhibited the highest viscosity and absolute ζ-potential value. The ΔBS and TSI values indicate that the stability of the broth samples followed a descending order of WSL>JZJ>JTM. The optimal stability of the broth was at 40, 20, and 50 minutes for JTM, JZJ, and WSL homogenization, respectively. In summary, it is suggested to use a high-pressure homogenizer to prepare steam-exploded broth for 20 minutes in industry.